Is it possible to sue my customer in Italy for not paying the fish we sent?

We are an exporter of marine fish here in the Philippines. Before Christmas of 2012, a Filipino who is already residing and his family in Italy came to our company to deal with us regarding our marine fish. He works in a company in Italy as a worker at the same time as a partner, and because he is a Filipino we deal with him and trusted him. In our first shipment last Jan 18, 2013, their company paid us. In the second shipment last 29 January 2013, they did not contact me after the fish arrived, when I call them and demanded their payment they told me that they will not pay because they have a problem with their local customers. I became angry and started shouting each other and to make it short told me that even a cent they will not give me anymore because they cannot sell the fish because they have problems with their customers not on the fish we sent.

I would like to know if I could still collect the money with them? Can I sue their company?

Theoretically, you can sue them for collection of sum of money, just file the case in the court where your company resides.

However, for practical purposes, its very difficult to sue and enforce the summons as well as the court's judgment considering that your client is already residing in other country. Its an expensive and time consuming suit.